.Additional testing
is in progress or planned in both northern and southern Vietnam.
However, there are significant questions raised by media reports on
prior cases. In Hau Giang samples were only available from one of the
first four cases. However, the 19 year old brother was initially
seen at a general hospital prior to transfer to the center specializing
in Tuberculosis and Lung Diseases. Even though he was young, had
symptoms of avian flu, and was from a province experiencing outbreaks
of avian flu, no samples were collected. Similarly, there were no
samples collected from his cousin, who was from the sample province and
had the same symptoms. Likewise, an unrelated 24F was also at the
same hospital with the same symptoms from the same province, yet there
are no available samples.

Now, almost a month after the first admission on July 19, additional
deaths of children or young adults are being investigated, although in
many cases samples are not available:

"Specimens from a small number of additional patients, from both
northern and southern parts of the country, are ... being tested," WHO
said.

The authorities were also exploring cases of severe pneumonia in an
unspecified number of children and young adults, which mostly resulted
in death over the past three weeks, according to the Geneva-based
organisation.

"Specimens are not available for all of the fatal cases," it said in a
statement."

Tests that are H5 or H5N1 positive have been obtained in both northern
and southern Vietnam, although northern Vietnam has no reported cases
of avian flu, even though one of the fatalities ate sick birds prior to
onset of symptoms and chickens of a neighbor of the other northern
fatality have died.

Only of the above suggests that more cases will test positive and the
current outbreak in Vietnam may be more serious than the earlier
outbreak. Further recombination by H5N1 isolates would not be
surprising. The avian influenza population in Asia is extremely
unstable and the H5N1 isolates from earlier in the year have acquired
polymorphisms previously seen only in non-H5N1 isolates, such as H1N1,
H1N2, and H3N2 from humans and swine, or H9N2, N9N1, and H6N1 found in
other avian species.